OOPS-1980CMP4: Unable to send merge directive to <email address hidden>.

I'm trying to send a merge directive to the <email address hidden> email address, as described here:
https://help.launchpad.net/Code/Review#Email%20interface

However, when I try to send it through Gmail as an attachment I get this email response:
[quote]
Launchpad encountered an internal error during the following operation: creating a merge proposal from message with subject Merge request for gradle-templates. It was logged with id OOPS-1980CMP4. Sorry for the inconvenience.
[/quote]

Here is my Bazaar information:
[quote]
Bazaar (bzr) 2.3.3
  Python interpreter: /usr/bin/python 2.6.1
  Python standard library: /System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6
  Platform: Darwin-10.7.4-x86_64-i386-64bit
  bzrlib: /Library/Python/2.6/site-packages/bzrlib
  Bazaar configuration: /Users/elberry/.bazaar
  Bazaar log file: /Users/elberry/.bzr.log
[/quote]

I used the following command to create the merge directive:
[quote]
bzr send lp:gradle-templates -o fix.merge
[/quote]

It's the fix.merge file that I'm sending over via Gmail as an attachment.

I cannot use 'send' to email the directive directly because my Mac is not set up to handle email.